Spring-tension device.



A, H. KIRK.

SPRING TENSION DEVICE.

APPLICATION FILED FEB.19, 190a.

Patented July 19, 1910.

WASMINGYON. n. c.

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ALVA H. KIRK, OF MINNEAPOLIS, MINNESOTA.

SPRING-TENSION DEVICE.

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To all whom it may concern:

Be it known that I, ALVA I-I. KIRK, a citizen of the United States,residing at Minneapolis, in the county of Hennepin and State ofMinnesota, have invented certain new and useful Improvements in Spring-Tension Devices; and I do hereby declare the following to be a full,clear, and exact description of the invention, such as will enableothers skilled in the art to which it appertains to make and use thesame.

My invention has for its object to provide an improved spring adjustingdevice, and to this end it consists of the novel devices andcombinations of devices hereinafter described and defined in the claims.The said spring adjusting device is shown as applied for a particularpurpose, to-wit, as a spring tension device for a so-called impact platein my prior United States Letters Patent No. 881,135, issued of dateMarch th, 1909; and, in the present application, the said spring deviceis, for the purposes of illustration, shown as applied for the samepurpose; but it will, of course, be understood that it is capable ofgeneral applica tion wherever a spring tension device of the characterhereinafter described may be found desirable.

The said spring tension device is illustrated in the accompanyingdrawings, wherein the View shown is a side elevation, with some partsbroken away and some parts sectioned.

In the said drawing, the parts shown are indicated by the samecharacters that were used to designate the same in the said priorapplication. Referring to these parts, the numeral 3 indicates thebox-like casing, into which the running grain of the grain dampener isassumed to be delivered, by an inclined run-way (not shown) and thenumeral 4 indicates a feed trough which receives from said casing 3.

The numeral 10 indicates part of a water supply conduit and the numeral11 indicates a column that is rigidly secured to the top of the casing 3and is provided with an extended base 11 The numeral 12 indicates abox-like casing which is supported by the column 11 and, in turn,supports a bearing 14.

The numeral 15 indicates a short shaft which is mounted in the box 12and bearing Specification of Letters Patent.

Application filed February 19, 1908.

Patented July 19, 1910.

Serial No. 416,787.

14: and operates a water supply valve (not shown).

Two overlapped slotted arms 19 and 20 are connected by a pivotalcoupling 26. The arm 19 is secured to the outer end of the shaft 15, andthe arm 20 is pivoted to a bearing bracket 21, which, in turn, isrigidly supported by the standard 11. The arm 20 has an arm extension 20and a depending stem 23, to the lower end of which latter is rigidlysecured a so-called impact plate 22.

The improved spring adjusting device, as herein illustrated, comprises acoiled spring 29, a threaded rod 30, and a head or nut 31, the latterhaving a multiplicity (shown four) of fingers 32, the upper ends ofwhich are hooked or bent radially inward so that they work between thecoils of the said spring 29. The said spring 29, at its upper end, isattached to the end of the arm extension 20 The threaded rod is rigidlyanchored to the base extension or support 11 and is axially alined withthe said spring 29. Said coiled spring 29 is preferably tapered in adirection from its lower toward its upper end. The head 31 works as anut on the threaded rod 30. Furthermore, the said spring 29 should be sowound that when it is normally tight or solid, its coil should have thesame number of threads per inch as the threaded rod 30.

The spring 29 exerts a force which tends to hold the impact plate 22 inthe position indicated by dotted lines, in which position we will assumethat the valve, not shown, but which is carried by the shaft 15, is in aclosed position. It may be also stated that the impact plate is forcedinto the position shown by full lines by the flow of grain against thesame, which movement is resisted by the spring 29. By rotary adjustmentsof the head or nut 31, a greater or less portion of the spring 29 may bebrought into or cut out of action, so as to thereby vary the strength ofsaid spring. WVhen the impact plate 22 is in the position shown bydotted lines, the coils of the spring 29 will be drawn together. Hence,the head 31 and fingers 32 may be adjusted upward or clownward withrespect to the spring at such times, without varying the tension whichthe said spring will normally exert. It is, however, evident that theshorter the operative portion of said spring 29, the greater will be theforce required to move the said impact plate 22 or other part, themovementof which is resisted by said spring, any predetermined distanceaway from its normal position.

What I claim is:

1. A spring tension device comprising a solidly wound coiled spring, arelatively fixed rod axially alined with said spring and having threadscorresponding in direction of travel and number per inch to the closedcoils of said spring, and a head working as a nut on said rod and havinga multiplicity of fingers with in-turned ends working between the coilsof said spring, the said head and fingers being adjustable to cut intoor out of action more or less of said spring, substantially asdescribed.

2. A spring tension device comprising a coiled spring, a relativelyfixed rod axially alined with said spring and having threadscorresponding in direction of travel and number per inch to the closedcoils of said spring, and a head working as a nut on the said rod andhaving fingers or projections that work between the coils of saidspring, the said head and fingers being adjustable to cut into or out ofaction more or less of said spring, substantially as described.

In testimony whereof I afiiX my signature in presence of two witnesses.

ALVA H. KIRK.

WVitnesses:

H. D. KILGORE, MALIE HonL.

